There has been known a rotor of a motor used in rotary compressors such as scroll compressors (see, for example, Patent Documents 1 to 5). A 4-pole rotor generally includes a rotor laminated steel plate, a permanent magnet arranged inside the rotor laminated steel plate to form four magnetic poles, rotor end plates located on both end surfaces of the rotor laminated steel plate, and balance weights that counteract centrifugal force acting on the eccentrically rotating part of the compression mechanism. The rotor laminated steel plate and the rotor end plates are fixed by four rivets, and the balance weights are fixed to the rotor end plates, respectively, by using two of the four rivets.
As 6-pole rotors efficient in reducing vibration and noise, there have been known rotors having a structure in which the rotor laminated steel plate and the rotor end plates are fixed by six rivets or three rivets (see, for example, Patent Document 5).
Patent Document 1: Japanese Patent Application Laid-open No. 2000-125492
Patent Document 2: Japanese Patent Application Laid-open No. 2000-287424
Patent Document 3: Japanese Patent Application Laid-open No. S63-28250
Patent Document 4: Japanese Patent Application Laid-open No. H4-237891
Patent Document 5: Japanese Patent Application Laid-open No. 2005-245148